Method of testing materials



v March 4, 1930. E. E. BLANKENSTEIN El AL 8, 6

METHOD OF TESTING MATERIALS Filed Nov. 15, 1927 I {fife/#026 fdwzdbf/miewlk/h [hes/arm Cay/fer Patented Mar. 4, i930 rimmers, A'ssIGiIoRs T0 wasrnnn'nnnornrc; COMPANY, r reonronn'rnnj or NEW.

Yon-K; i Y.',' A'YCORPOBATIONDF' NEW YoRK METHOD; on mrsrme- MATERIALS:

Application filed November 15,-1 B2:7.' Serial No. 233,405., r

This inventionrrelates J to methods of testing materials, and more particularly to methods-ofa'ndapparatus-for testinggranula-r carbon used in transmitters.

performing; certain testson granular,

material-,1 such as carbon used extensively in telephone transmitters and the: like, it

heretofore=.been the practice in some 1nst-ances 1 to includetransmitters containing, samples or lotsof carbon types of testing] apparatus. In employing suehapparatus fo-rjconducting the tests, care must be gexercisedin order to maintain the, uniform operation: of the testing apparatus I r so, that-"the variations determined by the suecessiaze: tests; which: are conducted will serve tov :indlcate variations: in the characteristics of the carbon tested and not, variations.

in cooperative, relationship oi the parts con- 1 stituting the testing apparatus; Ininstances where thear rangemen-t of thextrans-' mitter parts must be adjusted to permit theassociation therewith of granular carbonyit;

requires skill and the: expenditure of considerabletime to make such adjustments.v Thus,-

one of theprObIemSpresented in conducting I testsion granular carbonresides in the elimi- The primary objects-of this invention are nation of variationsresulting from; factors other than the? inherent"characteristics of the arbon tested. 1 1

the: provision ofsimple and eiiicientmethods of expeditiously;testingmateriais.;

In accordance with the general features of the invention, one embodiment thereof by means of which the improved method of testing .may be effectively practiced, consists "ofalgranular carbon,-

in a transmitter having ai vibration-respon-q which is apertured to allow; the convenient insertion andremovalf By such ameans-a,

sive means i or button;

method may be conveniently practiced wherein samplesof carbon maybe success sively, tested under identical conditions within aitransmitterfof known eie ctricaland j 5 mechanical characteristics" without dismantlihgariybf the transmitter parts during the. course of the testing operations. :The method-may alsobe practiced which enables o afcomparativei cross;checktesting of carbon Within I certain rnay be practiced; a telephone transmitter samples; with standard: lotss ofi carbhn; with dispatch anddesired accuracy in such a man ner: as to positively eliminate, the introducwhen considered in connection; with th o eomp'anyi-ng drawing whereinf Fig; 11s a s de elevationalo-viewqof a-transsmitter equipped with. a vibration responsive? 'rneansfor button which is representativ eof one embodiment of thevinvention byjimeanss of which the improved method of testingy tice'd; r o I Fig, 2 is a sectional view otthe transmitter;

button taken on the line 22 of Fig portion thereof being-ishowvniir elevation; 7-

Fig. 3 is; a circuitdiagramfor-illustrating;

ED-wAnD EVANS" BLANKENSTEIN Ann CHESTER MILLER Cowman," or emeneo,

one of the electricaltests to' whioh transfemitters "are subjected and J FigSJt and 5 are d'agrammatic representationsof a seriesof transmitters thes'efig ures being shown for the purpose of morel clearly setting; oforth ithe improved. crosscheck method of testingygranu'lar carbon-1 f f Referring now to the drawings; 1 wherein like nuine rals have' been employed to desi'g;

pose of illustrating one embodimen-tvotthe? 7 so. nat'e sim lar parts-throughout t11e:J?aIi1Is: figures, 1t will be observed-that for the-puny invention whereby themethods of testing;

denoted generally by the" numeralflO, is disclosed in liig 1, this transmitterbeing'show n 1 partially in section forthe purpose ofirirtire clearly showing a-vibration responsive-meanes or button ll convenient-1y:mounted therein;

This-;transmitterv button 11.includes aifront electrode, assembly denotedgenerally byfthe; numeralj12- (Fig. 2) which is centrally *sup-.

ported a diaphragmfll which isjmar ginallysecured in position by means a; clamping ring 15. The button 11' also ins chides-a back electrode assembly indicate df bythenumeral 16 having a flange 18 which."

forms an enlarged portion: vof. a shank 119;;

A space or chamber 20 'ispre sented between? 6: granularcarbo'nf may be efiiectiveiy pram the front and back electrode assemblies 12 and 16, which serves to retain a supply of granular carbon 22in position between said assemblies. It will be clear that the back electrode 16 is stationary while the front electrode is movable in response to vibrations transmitted thereto.

In order to conveniently supply the granular carbon 22 to the chamber an aperture 23 is provided in the outer wall of the chamber which extends tnrough the flange 18, the lower extremity of the aperture terminating *ithin the chamber 20 and the upper extremity thereof terminating within a projeeting portion 2a and threaded to receive a knurled plug 26. To supply the chamber 20 with granular carbon it is only necessary to unthread the plug 26 and introduce the carbon within the aperture 23. Likewise, the carbon 22 may be conveniently removed from the chamber 20 by positioning the transmitter button 11 so that the aperture 23 positionedat the bottom thereof to permit carbon to be removed from the chamber by the force of gravity; Having a conveniently refillable vibration responsive means or transmitter button 11 as described, renders possible the testing of successive samples of carbon without the necessity of dismantling the transmitter parts for the purpose of removin carbon from or refilling the chamber 20.

Tn order to test samples of carbon having unknown characteristics, it is desirable in certain instances to make comparative tests with similar samples of standard carbon having known characteristics. In such instances the apparatus just described serves'very effectively to permit the performance of such comparative tests with very great accuracy.

By reason of the fact that the transmitter button 11 is refillable without necessitating the dismantling of any of the transmitter parts, successive tests on samples of carbon may be made without introducing any errors which might result if mechanical adjustment of the transmitter p'arts should be made be tween each successive testing operation.

Thus, for example, if a sample of carbon is introduced within the chamber 20 and subjected to a resistancetestwhich might be performed by including the transmitter within an electrical circuit 27 as clearly shown in Fig. 3, this sample could be removed from the chamber and another sample of carbon.

introduced and subjected to thesame resistance test wlthout rearranging transmitter parts. Any differences which might result in subjecting'these two samples to the above 'mentioned test would clearly be due to the operating arrangement of the transmitter parts must be taken into consideration in order to accurately determine variations in the carbon to be tested from a known lot of standard carbon. Thus, for example, such factors as variations in the operating characteristics of the electrical testing apparatus other than the transmitter proper which might be included Within the circuit 27 or other testing circuits would have a tendency of introducing errors or differences in results obtained upon the performance of successive tests. Obviously, the determination of differences under such conditions might not in dicate the variation in quality of the tested carbon alone, but might also indicate variationsin the operating conditions of the testing apparatus. Other factors which should be considered are the variations in humidity thereof, may be employed, fiveof these transmitters indicated by the letter S being provi'ded with a supply or lot of standard carbonhaving known characteristics. The remaining half ofthese transmitters indicated by the letter T are provided with a sample of test carbon from a supply thereof having unknown characteristics and all of these quantities contained within the ten transmitters are then subjected to certain tests such, for example, as the resistance test which i may be performed by the use of the apparatus disclosed in Fig. 3. Upon the completion of these tests, transmitters containing the standard carbon are refilled with samples of the test carbon and the transmitters containing the test carbon arerefilled with the standard carbon. j

From the foregoing it will be understood that these transmitters may be refilled without disturbing the arrangement of the cod erating parts thereof. The carbon :in the refilled transmitters is now subjected to tests similar to those just described, and thus" it will be apparent that upon the completion of all of these tests all of the transmitters will have beenused to test quantities of standard carbon and likewise all of said transmitters will have been used to test in a similar manner samples of test carbon. The results or essees ard-aearbonr Withinithestesting apparatns .are

- summed up iandidivided' by the total. number i g of? transmitters :wvhich in. the particu1ar t in 'gstancewill beten. Likewise the results.ob- ;ta-ined thesapparatusgby using stheetest carbon i will he; summed-11p and. divided; in ;a v

' "tes ing apparatuswmchisyused. QItgWillfllSO.

. be understood that the descr-ihed,crossrcheck r :ing piece partsiandi the like,Wherethe= testing 75 apparatus isfof acolnplieateddesign ornasimilar Y manner. 'i-Thej -.clifierence between the results obtained by using thestandard can bonand thoseobtainedbyusingthe testycar-.

if bohwvil-Lserve to accurately, indicate the dif- -ferenee in i theuqnality orgcharacteristics, of ;-the '.qua11tity;,0f test carbon fromVW-hich the 15 v fact; that thexarrangement of; the cooperative samples revere selected as compared with: the characteristics. of; the; standard carbon. The

' v parts of the transmitters is not disturbed ,dur-

: ing the performance of; the above d s ribed tests, pessitively eliminate the Q introduc ion of anyterrorsor cliifier-enceswhich-mig ethe wise re ult if 11 the transmi e s w re dis, mantled in: erde fto efill hemifor eeh tes BvsemplQy ng en rhel f he to l numb ef transmitte so iorites ing. ta d arb n Handth letherh l -ier t sting. samp e -0f ce ben having mknewn haracte st c e d h reversing th .operat n iby 'r ple i g t ,eleetrieal "t sting n .q ientiti etenelerd end e carb n wit qu.ent. t.iesxeft estiend stand b n;

p e velysthe b;t i -.i g Ql U I eliminat finale u t. 0t eeyvariati n dif te ts 7 eq red en he ef r s oul be im t d only bythe-e epe Q theepnend d telalme- 1 j in ee es n the e er-etiegieher e iet :ef th neretue in wh t e tnensmitters ere in luded -peeiti e 'y feslt i1 the Wordsi flthefire eep .efi

lends n l nliee eni teste i not pne i e enetiesrumle ee jtein :p et red -51 enssnsli heeee ndsreep. e hen wee,

era ingensieeent ee y-difieeent co ditions, the e servin epeeetie ee dit eee o heep: Re-retee I d f erence -Wil e efiee -the; v.

elie :enlrv twee; met ehe ee er ie fathe .testegliee iben-wi be d ermin d- ;11inrbsvementiee dvbele eins ou 'e e tw l be. more apparent when it is observed tha-t 'eeeel;,ei .m e ete the gr upe tene e m .te ezere;seleie ted'zteeendi iee in assembly to" operating conditions, and-deter- V is thet -e ult nt. haree ristie le h ee em yt te t her kn pertthe testing operations of the apparatus and herefo e any ve ie iene in 'bezbe lse eeleut- .WhiIe the invention cable for use in connection with the testing scribed readily lends itself for-use in con-v of granular carbon and the like, it Will be clear that the cross-check method'just de nection with the testing of numerous types of material or apparatus, 'Wherein' a possible smgle variableiactor or characteristic'is to" .7 be determlned Thus, Whencertain characteristics of parts or elements, such as the eti ne th -t stend such operations" isparticularly appli- 7 on is s nsubjec ing n operative f-aesemi ly f i ee etins in r w ep t es e'nditiene, d te mi ing the ch racte istic of t e e mblyi; pleeing e ie efhe meme e :pe havin rt enknewn" chara teristic, vm int injing: the aseen ble l r et en efathereme insfpe ts d ri g;ther pleeemen r-efi h rpa h'ege neu jeet ng theee emb yt -epere positively eliminate or 1 balance out "any noticeab1e-..variations in thetopenationoif the vmethod of; testing; may. be employed in testture and inWhichivariationsinitheoperation 5 of theapparatns may considerably from time toltime. ;B y praeticingthe method'd scribechnll of these variations resnltingtrom erego ilg i wi l, be. seen of vibration responsive means having s -n ;-sle; e me whi h mightkint etluee va ia le teeter, eme me nti y e yg a iularearmeily ther ennlieatioes -;Wh -r eemparat That 15- claimed is i {14 Th meth d lf-1 te ti g theehereet rie cs. of .thesfirst m iti ne par '2: The :me hed: s t-te ting materials whi .ee ts i incl ding ren hevingan ni tlmewn e r et rls l wi h o he assemb v mater al wh c -een 'ste inieddinglperthe ing en unkno n iehe ieete iete t =eeope ating gp-er Jh-avii .k- PWI e reeteliiet e e ren rt he assemb y it ePereti e sub n the e embly of pa t -t Ope at ngrendit ons, an [measur ng t e epe i es o th a embly to determin the operatio the Complicated ,a1 -11angement refth oop rating pa ts may b balanced out .s vthet th u timeteresnlt obtained int perifer l ng the tes lnel he. effectedJo-y any v rie ens. in'the oper tien; efthe testing 3P" I r -fetus, F om thezt .the the n ention. he.heeritleseribedine e ,n etieni ith hee es in-g of a; partieulero yp vhen which might i certaineharaetee ist cs from ;a des red standard, and it is:v to be un ers dgthe jth i n nti ni sen-able of Q5 llO parts Of know ,eh ree ri ti s to c mpleteth sembly opera ve, subject ng t e e mple e min * i et l ;m terielerw-hieh ing condition; and determining the charac- ISSQ bL dIQ a t eof. and ee er the; as r .teriet e e th eeeeeimv to; determine the ee eretwe ,ehe-reeteri 'tiesef-i hei unkn wn ;part., v t

l. The method of testing materials, which consists in subjecting an operative assembly of cooperative parts having known characteristics .to operating conditions,"determining the operativeness of the assembly, replacing one of the parts with a part'havingan unknown characteristic, maintaining the as: sembled relation ottheremaining parts during the replacement, then subjecting the thus assembled parts to like operating conditions,

and again determining the operativeness of the assembly to determine the comparative characteristics of the unknown part.

5. The method of testing'materials, Which consists in subjecting an assembly of cooperative parts including a standard part to testing conditions, similarly subjecting another like assembly including a part having an unknown characteristic to testing conditions, replacing the standard and unknown parts with unknown and standard parts, respectively, and then subjecting these assemblies to testing conditions to determine any variation in the unknown parts from the standard parts. r

6. The method of testing materials, which consists in associating 'a sample of granular carbon with a vibration responsive means, subjecting the vibration responsive means to operating conditions, determining the effect of said subjection, removing the granular carbon after testing, and maintaining the relationship of the cooperating parts of the vibration responsive means during the removal of the carbon. j

7; The method of testing granular materials, which consists in associating a quantity of granular material with a vibration responsive means of known characteristics, subjecting the vibration responsive means to operating conditions, replacing the material with another quantity of granular material, maintaining the relationship of the cooperating parts of the vibration responsive means during the replacement of the material, and determining the comparative-effect of the subjection upon the different materials, 7 V

8. The method of testing granular materials, which consists' in associating a, sample of granular material having an unknown characteristic with a vibration ITBSPODSIVG,

means, subjecting the vibration responsive means to operating conditions, replacing the sample of material with a quantity of material having a known characteristic, maintain ing the relation of the cooperative parts of the vibration responsive means during the replacement of the materials, then subjecting the vibration responsive means to similar operatingconditions, and determining the effect ofthe subjection on the different materials. V s

-9. The method of testing granular materials, whlch consists in success1vely assoclatmg quantities of granular materlal w1th a rials. V p

10. The method of testing granular mate;

vibration responsive means,maintaining the relation of the cooperatmg parts of the v1- of the granular material, and ascertaining the variatlon between the dlfierent materials, which consists in subjecting a quantity of standardgranular material to a test within a vibration responsive means, subjecting a similar quantity of granular material having an unknown characteristic to a test with-;

in another vibration responsive means, replacing the quantities of standard and run known material, respectively, with quantities of unknown and standard material, repeating the testing operations, maintaining the; relation of the cooperative parts of the V1- bration responsive means throughout the testing operations, and comparing the results of the tests to determme the quality of the material having an unknown characteristic.

11. The method of testing granular carbon for use with transinitters,wliich consists in subjecting a sample of carbon'within a transmitter to a test, refilling the transmitter with another sample of carbon material, repeating the testing operation, maintaining the relation of the cooperating parts of the transmitter cluringthe refilling thereof, and

comparingthe results of the tests to determine the relative quality of the samples.

7 12.? The method of testing material which consists in alternately subjecting assemblies ofcooperative parts including a standard part, and assemblies of cooperative parts including a part having unknown characteristics to testing conditions, replacing the standard parts and unknown parts with unknown and standard parts, respectively, subj ecting the assemblies to the same testing conditions, and determining the mean variation of the unknown parts from the standard parts. 4

In witness whereof, We hereunto subscribe our names this 31st day of October, A. D.

r EDWARD EVANS BLANKENSTEIN.

I CHESTER MILLER COULTER;

ZOU 

